Automated tuning of a service configuration

ABSTRACT

Methods and systems for automated tuning of a service configuration are disclosed. An optimal configuration for a test computer is selected by performing one or more load tests using the test computer for each of a plurality of test configurations. The performance of a plurality of additional test computers configured with the optimal configuration is automatically determined by performing additional load tests using the additional test computers. A plurality of production computers are automatically configured with the optimal configuration if the performance of the additional test computers is improved with the optimal configuration.

This application is a divisional of U.S. patent application Ser. No.13/710,013, filed Dec. 10, 2012, now U.S. Pat. No. 9,053,070, which ishereby incorporated by reference in its entirety.

BACKGROUND

Tuning the configuration of a service on a computer system to handle adesired load is typically a manual process. In other words, a tuningprocess typically involves a user manually tweaking different attributesof the service or the underlying system in the hopes of improving theperformance of the system running the service. The attributes to betweaked may be as specific as the numbers of threads in different threadpools but may include any aspect of the service that might affectperformance or throughput. Multiple attributes may need to be manuallymodified many times in an effort to improve the performancesignificantly, especially if performance is dependent on multipleinterrelated attributes. For heterogeneous multi-host web services thathave specific targets in terms of throughput, latency, or stability, thetuning process may be especially complex and time-consuming.

A typical approach to this manual tuning process involves trial anderror. A user may making some initial guesses on optimal values, put theservice into production based on the guesses, and manually analyze theload it can handle. The user may then tweak the values even further,again based on guesswork. In some circumstances, parts of the systemwill change dramatically over time, thus making the original estimatesoutdated. However, because this approach to tuning is manual andtime-consuming, the tuning may not be performed on a regular basis. As aresult, outdated and inefficient settings may remain in place until theyhave significantly adverse effects on performance. When performanceestimates are outdated or entirely absent, hardware resources may bewasted on systems that are not operating optimally. For example, in afleet of 10,000 hosts, a 10% improvement in throughput can mean asavings of 1000 hosts as well as savings in resources such as networkbandwidth and power consumption.

Accordingly, it is desirable to have efficient techniques for tuningservices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example system environment for automated tuning ofa service configuration, according to one embodiment.

FIG. 2 is a flowchart illustrating a method for automated tuning of aservice configuration, according to one embodiment.

FIG. 3 illustrates an example of a service configuration that may beautomatically tuned, according to one embodiment.

FIG. 4 illustrates aspects of a load generator module, according to oneembodiment.

FIG. 5 illustrates aspects of a load testing process for determining anoptimal configuration, according to one embodiment.

FIGS. 6A and 6B illustrate examples of performance variations fordifferent values of a configurable parameter, according to oneembodiment.

FIG. 7 illustrates an example computing device that may be used in someembodiments.

While embodiments are described herein by way of example for severalembodiments and illustrative drawings, those skilled in the art willrecognize that embodiments are not limited to the embodiments ordrawings described. It should be understood, that the drawings anddetailed description thereto are not intended to limit embodiments tothe particular form disclosed, but on the contrary, the intention is tocover all modifications, equivalents and alternatives falling within thespirit and scope as defined by the appended claims. The headings usedherein are for organizational purposes only and are not meant to be usedto limit the scope of the description or the claims. As used throughoutthis application, the word “may” is used in a permissive sense (i.e.,meaning “having the potential to”), rather than the mandatory sense(i.e., meaning “must”). Similarly, the words “include,” “including,” and“includes” mean “including, but not limited to.”

DETAILED DESCRIPTION OF EMBODIMENTS

Various embodiments of methods and systems for automated tuning of aservice configuration are described. Using the systems and methodsdescribed herein, intelligent and automated tuning of a service may beperformed to determine an optimal configuration on test computers beforethe optimal configuration is put into production. The optimalconfiguration may be rolled back if it adversely affects the performanceof production computers. In one embodiment, the automated tuning may beapplied to any numerically configurable parameter that may affectperformance, throughput, or stability. The optimal configuration may bedetermined such that a user-specified performance goal is met, and theuser need not be aware of the specific configurable parameters that aretuned.

FIG. 1 illustrates an example system environment for automated tuning ofa service configuration, according to one embodiment. The example systemenvironment may comprise an automated configuration tuning system 100.The automated configuration tuning system 100 may include variousmodules such as a load generator module 110, a load testing module 120,and a performance monitoring module 130. The automated configurationtuning system 100 may comprise one or more computing devices, any ofwhich may be implemented by the example computing device 3000illustrated in FIG. 7. In various embodiments, the functionality of thedifferent modules (e.g., load generator module 110, load testing module120, and performance monitoring module 130) may be provided by the samecomputing device or by different computing devices. If any of the loadgenerator module 110, load testing module 120, and performancemonitoring module 130 are implemented using different computing devices,then the modules and their respective computing devices may becommunicatively coupled, e.g., via a network. Each of the load generatormodule 110, load testing module 120, and performance monitoring module130 may represent any combination of software and hardware usable toperform their respective functions, as discussed as follows.

The load generator module 110 may generate a plurality of test loads 115for use in the load testing of a service 140. For example, if theservice 140 is associated with an electronic commerce (e-commerce)merchant, then the service may be configured to perform one or moresuitable operations such as generating a web page (e.g., a productdescription page for a product offered for sale by the merchant),completing a sale or other transaction between the merchant and acustomer, verifying a payment presented by the customer, etc. Each testload may comprise data associated with a plurality of transactions orother operations that are processed by the service 140. The test loadsmay vary in transaction frequency (e.g., transactions per second). Thetest loads may be generated by sampling actual production transactionsor by generating synthetic transactions. The functionality of the loadgenerator module 110 is discussed in greater detail below with respectto FIG. 4.

Turning back to FIG. 1, the automated configuration tuning system 100may be communicatively coupled to a plurality of other computer systems,any of which may be implemented by the example computing device 3000illustrated in FIG. 7, over one or more network(s) 150. The automatedconfiguration tuning system 100 may be communicatively coupled to a testhost pool 160 comprising a plurality of test computer systems. Forpurposes of illustration, the test host pool 160 is depicted in FIG. 1as including three test hosts 161, 162, and 163. However, it iscontemplated that any suitable number of test hosts may be used.Software implementing the service 140 may be installed on, and executedby, each of the test hosts 161, 162, and 163.

The test host pool 160 may be used to determine an optimal configuration145 for the service 140. The load testing module 120 may use the testloads 115 to perform load tests using one or more of the computersystems in the test host pool 160. In one embodiment, a first set ofload tests may be performed using a single one of the test hosts, e.g.,test host 161. Each of many test configurations of the service 140, suchas configurations 141, 142, and 143, may be subjected to load testsusing the test loads 115. In one embodiment, a plurality of the testhosts 161, 162, and/or 163 may each be used for simultaneous andindependent load testing of different test configurations. Eachconfiguration of the service 140 may comprise a different set of valuesfor one or more configurable parameters of the service. An example ofconfigurable parameters is discussed below with respect to FIG. 3.Turning back to FIG. 1, in one embodiment, each test configuration maybe subjected to test loads 115 of increasingly greater transactions persecond. Based on the results of the load testing of the different testconfigurations, the load testing module 120 may select an optimalconfiguration 145 from among the test configurations. The optimalconfiguration 145 may comprise optimal values for the one or moreconfigurable parameters of the service 140.

In one embodiment, the load testing module 120 may further validate theoptimal configuration 145 by performing additional load tests on aplurality of test hosts 161, 162, and/or 163 using the optimalconfiguration. The additional load tests may determine whether theoptimal configuration 145 is scalable from one host to many hosts. Ifthe optimal configuration 145 adversely affects the performance of thetest host pool 160, then the individual hosts in the test host pool 160may be reverted to an earlier configuration of the service 140. Thefunctionality of the load testing module 120 is discussed in greaterdetail below, e.g., with respect to FIG. 5.

Turning back to FIG. 1, the automated configuration tuning system 100may also be communicatively coupled to a production host pool 170comprising a plurality of production computer systems. For purposes ofillustration, the production host pool 170 is depicted in FIG. 1 asincluding three production hosts 171, 172, and 173. However, it iscontemplated that any suitable number of production hosts may be used.Software implementing the service 140 may be installed on, and executedby, each of the production hosts 171, 172, and 173. The production hosts171, 172, and 173 may comprise computer systems used in conducting theprimary or real-world operations of an entity. For example, if theentity is an e-commerce merchant, then the production hosts 171, 172,and 173 may be used to process real-world transactions with customers.

Once the optimal configuration 145 has been selected and validated bythe load testing module 120, the optimal configuration may be deployedto the production hosts 171, 172, and 173. In deploying the optimalconfiguration, the configurable parameters of the service 140 may be setto the optimal values in each host in the production host pool 170. Theperformance monitoring module 130 may then monitor the performance ofthe service 140 with the optimal configuration 145 in the productionhost pool 170. In one embodiment, the performance monitoring module 130may receive performance data from a performance monitoring agent runningon each production host and then analyze the performance data. If theperformance monitoring module 130 determines that the optimalconfiguration is adversely affecting the performance of the productionhost pool 170, then the individual hosts in the production host pool 170may be reverted to an earlier configuration of the service 140.

FIG. 2 is a flowchart illustrating a method for automated tuning of aservice configuration, according to one embodiment. As shown in 200, aplurality of test hosts may be provisioned. Provisioning the test hostsmay comprise configuring the test hosts to match the specificationsand/or configuration of one or more production hosts, e.g., productionhosts whose performance is sought to be tuned. In one embodiment,provisioning the test hosts may comprise installing and/or configuringthe service 140 along with other associated software. In one embodiment,the test hosts may be provisioned by borrowing hosts from the productionhost pool 170 on a temporary basis. However, safeguards may beestablished (e.g., to delay the automated tuning) if the borrowing ofthe production hosts would adversely affect the production environment.In one embodiment, the test hosts may be provisioned by selecting themfrom a pool of available test hosts based on the similarity of theirhardware configuration to the production hosts running the service 140to be tuned. In one embodiment, the number of test hosts may beconfigured by a user. In one embodiment, the user may specify apercentage of production hosts to be temporarily provisioned as testhosts.

As shown in 205, a plurality of test loads may be generated. The testloads may be associated with data processed by the service 140 whoseperformance is sought to be tuned. The generation of the test loads isdiscussed in greater detail below with respect to FIG. 4.

Turning back to FIG. 2, as shown in 210, a baseline performance of theservice may be determined. In one embodiment, the baseline performancemay be determined by running baseline load tests of the service 140 onone or more of the provisioned test hosts using an existingconfiguration of the service. The baseline performance may be determinedfor a single test host and also for a plurality of test hosts. Thebaseline load tests may use the test loads generated in 205. In anotherembodiment, the baseline performance may be determined by monitoring thereal-world performance of production hosts processing productiontransactions. The baseline performance may measure any suitableperformance attribute(s), such as memory usage, processor usage, networkthroughput, network latency, response time, etc. In one embodiment, theperformance attribute(s) measured for the baseline performance may berelevant to a performance goal specified by a user.

As shown in 215, one or more load tests may be performed on a singletest host for each test configuration. The load tests may use the testloads generated in 205. Each test load may comprise data associated witha plurality of transactions or other operations that are processed bythe service 140. For each test configuration, the test loads mayincrease in transaction frequency (e.g., transactions per second) foreach successive load test. In one embodiment, the duration of each testmay be user-configured. The load testing is discussed in greater detailbelow with respect to FIG. 5.

Turning back to FIG. 2, as shown in 220, the optimal configuration maybe selected from among the configurations tested in 215. In oneembodiment, the optimal configuration may be determined such that auser-specified performance goal is met, and the user need not be awareof the specific configurable parameters that are tuned. The optimalconfiguration 145 may comprise optimal values for the one or moreconfigurable parameters of the service 140.

The optimal configuration may then be deployed to the entire set ofprovisioned test hosts. In deploying the optimal configuration, theconfigurable parameters of the service 140 may be set to the optimalvalues in the other test hosts. As shown in 225, one or more additionalload tests may be performed on a plurality of the provisioned test hostswith the optimal configuration. The additional load tests may also usethe test loads generated in 205. In performing the additional loadtests, a pre-production performance of the test hosts may be determined.The pre-production performance may measure any suitable performanceattribute(s), such as memory usage, processor usage, network throughput,network latency, response time, etc., that are relevant to theuser-specified performance goal.

As shown in 230, the pre-production performance of the test hosts withthe optimal configuration may be compared to the baseline performance.The comparison may involve the numerical values measured for one or morespecified performance goals. If the pre-production performance is notbetter than the baseline performance, then the tuning method may end,and the optimal configuration determined in 220 may be discarded.

If, however, the pre-production performance is better than the baselineperformance, then, as shown in 235, the optimal configuration may bedeployed to the production hosts. In deploying the optimalconfiguration, the configurable parameters of the service 140 may be setto the optimal values in the production hosts. Using the productionhosts, the service may then operate with the optimal configuration toprocess production traffic.

As shown in 240, the performance of the production hosts may bemonitored after the optimal configuration has been deployed. As shown in245, the performance of the production hosts with the optimalconfiguration may be compared to a previous performance of theproduction hosts with a previous configuration. The comparison mayinvolve the numerical values measured for one or more specifiedperformance goals. If the current performance is not better than theearlier performance, then, as shown in 250, the production hosts may bereverted to the previous configuration. On the other hand, if theperformance of the production hosts is improved by the optimalconfiguration, then the production hosts may be left to operate with theoptimal configuration, pending another tuning operation at a later time.

In one embodiment, the method shown in FIG. 2 may be performedautomatically and according to a schedule or on a periodic basis. In oneembodiment, a cron-like daemon or other suitable scheduling componentmay be used to invoke the automated service configuration tuning processat appropriate times. The schedule or periodic basis may be establishedby a user. A performance goal for the tuning operation may also beestablished by a user. In one embodiment, any of the operations shown inFIG. 2 may be performed automatically (e.g., without manual instructionfrom a user or otherwise independent of direct user control) and/orprogrammatically (e.g., by execution of suitable program instructions).

FIG. 3 illustrates an example of a service configuration that may beautomatically tuned, according to one embodiment. In processing requeststo generate responses, such as request 302 and response 332, a service300 may use multiple thread pools. In this example, a first thread poolmay include a first number of threads, including threads 304, 306, 308,and 310; a second thread pool may include a second number of threads,including threads 314, 316, 318, and 320; and a third thread pool mayinclude a third number of threads, including threads 324, 326, 328, and330. In one part of the workflow, a queue 312 may connect the firstthread pool and the second thread pool. In another part of the workflow,a single-threaded checkpoint 322 may connect the second thread pool andthe third thread pool. Using the systems and method described herein forautomated service configuration tuning, the numbers of threads in eachof the three thread pools may be optimized. In one embodiment, thethread pools may be optimized based on a user-specified performance goalthat does not specify the numbers of threads in each thread pool. Forexample, the user-specified performance goal may specify a higher-levelresult such as a particular transactions per second (TPS) and payloadwithin a particular latency or cost. In this manner, a layer ofabstraction may be placed between the user of the automated tuningsystem and aspects of the specific hardware and/or softwareconfiguration of the hosts being tuned.

FIG. 4 illustrates further aspects of a load generator module, accordingto one embodiment. The load generator module 110 may be implementedusing a suitable software component, such as a getNextTransaction()method 402. The getNextTransaction( )method 402 may be a generic loadgenerator function that may be configured by a user, e.g., to generatedifferent types of test loads 115. In one embodiment, thegetNextTransaction( )method 402 may be configured to use either aProduction Data Provider component 406 or a Distribution ProbabilityProvider component 404. In one embodiment, the genericgetNextTransaction( )method 402 may control overall transactions perseconds and concurrent connections. In one embodiment, the genericgetNextTransaction( )method 402 may record latency measures for eachtransaction and compute percentile metrics (such as P90 latency for aspecific TPS).

The Production Data Provider 406 may sample real-world production data(e.g., data associated with production transactions). The sampledproduction data may be saved to a Test Data Repository (TDR) 408 by abatch process. When test loads are generated, the Production DataProvider may fetch the next transaction out of the TDR 408. Accordingly,the Production Data Provider 406 may be used in conjunction with thegetNextTransaction( )method 402 when real-world transaction patterns aredesired for use with the automated tuning.

The Distribution Probability Provider 404 may generate synthetic testloads and may thus be used for modeling transaction patterns that arenot easily found in current production data. In configuring theDistribution Probability Provider 404, the user may define differentoperation types and the desired percentage distribution of theoperations. In the example shown in FIG. 4, the Distribution ProbabilityProvider 404 is configured such that transaction type X 410 is called20% of the time, transaction type Y 412 is called 70% of the time, andtransaction type Z 414 is called 10% of the time. The load generatormodule 110 may distribute the calls accordingly, and the user may supplyany suitable plug-ins or other service-specific program code to performthe calls. For example, if the system is a RESTful web service that iscurrently getting 10% POST requests and 90% GET requests, but it isexpected that it will later receive 30% POST requests and 70% GETrequests, then the Distribution Probability Provider 404 may moreclosely model the future pattern than the Production Data Provider 406.

In one embodiment, the automated configuration tuning system 100 mayautomatically detect the configurable parameters of a service along withthe current parameter values and the range of potential parameter values(i.e., the maximum and minimum values). The values of the parameters inthe test configurations may then be assigned within the appropriaterange. To implement this auto-discovery functionality, the automatedconfiguration tuning system 100 may include an administrativeapplication programming interface (API) to modify the configurableparameters. In one embodiment, each service being tuned may expose adebug hook that includes the following calls: getAllVariables( ) andsetVariable(variable,value). The getAllVariables( ) call may return aset of one or more variables (e.g., parameters) that can be tuned, andthe setVariable(variable,value) call may set the indicated variable tothe supplied value.

Each variable returned by getAllVariables( ) may include the followingdata: a unique ID, a data type, a minimum and maximum value to try, anda priority value. The unique ID describes the particular variable, e.g.,“ThreadPool-DoingWorkX” or “ThreadPool-DoingWorkY.” The data typeindicates a suitable data type of the parameter value, such as aninteger or a double-precision floating point value. The priority valuemay allow parameters to be separated into tiers such as priority 1 andpriority 2, where the automated tuning system may favor priority 1variables to be optimized over priority 2 variables, all other thingsbeing equal. The variables returned by getAllVariables( ) and set bysetVariable(variable,value) may include any configurable parameter, suchas, for example, a number of threads in a thread pool, a number ofelements to process before stopping, a percentage of records to sample,a buffer size, a number of database connections, or any other parameterwith a range that could potentially affect performance.

FIG. 5 illustrates further aspects of a load testing process fordetermining an optimal configuration, according to one embodiment. Theload testing process performed by the load testing module 120 may loopseveral times for all variables. In one embodiment, the load testingmodule 120 may perform iterations of a hill-climbing loop, in which thetransactions per second on a service are increased with each iterationto determine the maximum throughput that a host can handle within adesired latency and stability.

As shown in 502, baseline load tests may be run based on currentsettings. As shown in 504, the baseline performance and currentvariables may be stored. As shown in 506, load tests may be performedfor each priority and for each configurable variable. As shown in 508,load tests may be run to determine the best value for the variable. Theload testing process may start at a desired low transactions per second(TPS), run at that TPS for a specified amount of time (measuring thelatency of each individual call), and gradually increase the TPS. Theload testing process may compute percentile metrics and give the userthe ability to specify complex requirements. For example, the user mayspecify a requirement such as “run until it is no longer the case thatthe P50 latency is <300 ms and the P90 latency is <2500 ms,” in whichcase the maximum TPS is calculated based on latency requirements. Asanother example, the user may specify a requirement such as “optimizefor throughput,” in which case latency may be sacrificed if it producesan overall larger throughput. As yet another example, the user mayspecify a requirement such as “run until the failure rate is >0.1%.”

As shown in 510, the performance and best value for each variable may bestored. As shown in 512, the best value may be selected. As shown in514, the current settings may be modified based on the selection of thebest value for a particular variable. As shown in 516, the load testingprocess may stay in the loop indicated in 506 until the difference inperformance is sufficiently small or until a timeout condition isreached. As shown in 518, validation load tests may then be run based onthe new settings. As shown in 510, the optimized performance and newvariables may be stored.

Some configurable parameters may be completely independent, but othersmay affect one another. For example, let the configurable parameters bex and y, where originally x=10 and y=7. On the first pass, the loadtesting process may determine that for y=7, the best value for x is 13.However, the load testing process may then decide that for x=13, thebest value for y is 9. The load testing process may then iterate throughall the variables a second time and determine that for y=9, the bestvalue for x is 21. If the solution never converges, the load testingprocess will timeout as shown in 516.

Because some parameters may not scale linearly from a single host tomultiple hosts, the optimal configuration determined for a single hostmay be validated for multiple hosts before putting the optimalconfiguration into production. FIGS. 6A and 6B illustrate examples ofperformance variations for different values of a configurable parameter,according to one embodiment. In particular, FIG. 6A illustrates anexample graph 600 indicating how the number of threads affects thelatency per call. FIG. 6B illustrates an example graph 650 indicatinghow the number of threads affects the total throughput (in transactionsper second). In the example of FIG. 6A, if the user-specifiedperformance goal is that the P90 (i.e., 90^(th) percentile) latency isbelow 210 ms, then the automated tuning system may recommend 8 threads.On the other hand, if the user-specified performance goal is to maximizeoverall throughput, then the automated tuning system may recommend 11threads for a maximum of 42 transactions per second (but with a P90 of260 ms).

Illustrative Computer System

In at least some embodiments, a computer system that implements aportion or all of one or more of the technologies described herein, suchas the automated tuning configuration system 100, may include ageneral-purpose computer system that includes or is configured to accessone or more computer-readable media. FIG. 7 illustrates such ageneral-purpose computing device 3000. In the illustrated embodiment,computing device 3000 includes one or more processors 3010 coupled to asystem memory 3020 via an input/output (I/O) interface 3030. Computingdevice 3000 further includes a network interface 3040 coupled to I/Ointerface 3030.

In various embodiments, computing device 3000 may be a uniprocessorsystem including one processor 3010 or a multiprocessor system includingseveral processors 3010 (e.g., two, four, eight, or another suitablenumber). Processors 3010 may include any suitable processors capable ofexecuting instructions. For example, in various embodiments, processors3010 may be general-purpose or embedded processors implementing any of avariety of instruction set architectures (ISAs), such as the x86,PowerPC, SPARC, or MIPS ISAs, or any other suitable ISA. Inmultiprocessor systems, each of processors 3010 may commonly, but notnecessarily, implement the same ISA.

System memory 3020 may be configured to store program instructions anddata accessible by processor(s) 3010. In various embodiments, systemmemory 3020 may be implemented using any suitable memory technology,such as static random access memory (SRAM), synchronous dynamic RAM(SDRAM), nonvolatile/Flash-type memory, or any other type of memory. Inthe illustrated embodiment, program instructions and data implementingone or more desired functions, such as those methods, techniques, anddata described above, are shown stored within system memory 3020 as code(i.e., program instructions) 3025 and data 3026.

In one embodiment, I/O interface 3030 may be configured to coordinateI/O traffic between processor 3010, system memory 3020, and anyperipheral devices in the device, including network interface 3040 orother peripheral interfaces. In some embodiments, I/O interface 3030 mayperform any necessary protocol, timing or other data transformations toconvert data signals from one component (e.g., system memory 3020) intoa format suitable for use by another component (e.g., processor 3010).In some embodiments, I/O interface 3030 may include support for devicesattached through various types of peripheral buses, such as a variant ofthe Peripheral Component Interconnect (PCI) bus standard or theUniversal Serial Bus (USB) standard, for example. In some embodiments,the function of I/O interface 3030 may be split into two or moreseparate components, such as a north bridge and a south bridge, forexample. Also, in some embodiments some or all of the functionality ofI/O interface 3030, such as an interface to system memory 3020, may beincorporated directly into processor 3010.

Network interface 3040 may be configured to allow data to be exchangedbetween computing device 3000 and other devices 3060 attached to anetwork or networks 3050, such as other computer systems or devices asillustrated in FIG. 1, for example. In various embodiments, networkinterface 3040 may support communication via any suitable wired orwireless general data networks, such as types of Ethernet network, forexample. Additionally, network interface 3040 may support communicationvia telecommunications/telephony networks such as analog voice networksor digital fiber communications networks, via storage area networks suchas Fibre Channel SANs, or via any other suitable type of network and/orprotocol.

In some embodiments, system memory 3020 may be one embodiment of acomputer-readable (i.e., computer-accessible) medium configured to storeprogram instructions and data as described above with respect to FIGS. 1through 6 for implementing embodiments of the corresponding methods andapparatus. However, in other embodiments, program instructions and/ordata may be received, sent or stored upon different types ofcomputer-readable media. Generally speaking, a computer-readable mediummay include non-transitory storage media or memory media such asmagnetic or optical media, e.g., disk or DVD/CD coupled to computingdevice 3000 via I/O interface 3030. A non-transitory computer-readablestorage medium may also include any volatile or non-volatile media suchas RAM (e.g. SDRAM, DDR SDRAM, RDRAM, SRAM, etc.), ROM, etc, that may beincluded in some embodiments of computing device 3000 as system memory3020 or another type of memory. Further, a computer-readable medium mayinclude transmission media or signals such as electrical,electromagnetic, or digital signals, conveyed via a communication mediumsuch as a network and/or a wireless link, such as may be implemented vianetwork interface 3040. Portions or all of multiple computing devicessuch as that illustrated in FIG. 7 may be used to implement thedescribed functionality in various embodiments; for example, softwarecomponents running on a variety of different devices and servers maycollaborate to provide the functionality. In some embodiments, portionsof the described functionality may be implemented using storage devices,network devices, or special-purpose computer systems, in addition to orinstead of being implemented using general-purpose computer systems. Theterm “computing device,” as used herein, refers to at least all thesetypes of devices, and is not limited to these types of devices.

Various embodiments may further include receiving, sending, or storinginstructions and/or data implemented in accordance with the foregoingdescription upon a computer-readable medium. Generally speaking, acomputer-readable medium may include storage media or memory media suchas magnetic or optical media, e.g., disk or DVD/CD-ROM, volatile ornon-volatile media such as RAM (e.g. SDRAM, DDR, RDRAM, SRAM, etc.),ROM, etc. In some embodiments, a computer-readable medium may alsoinclude transmission media or signals such as electrical,electromagnetic, or digital signals, conveyed via a communication mediumsuch as network and/or a wireless link.

The various methods as illustrated in the figures (e.g., FIGS. 2 and 5)and described herein represent exemplary embodiments of methods. Themethods may be implemented in software, hardware, or a combinationthereof. In various of the methods, the order of the steps may bechanged, and various elements may be added, reordered, combined,omitted, modified, etc. Various of the steps may be performedautomatically (e.g., without being directly prompted by user input)and/or programmatically (e.g., according to program instructions).

Various modifications and changes may be made as would be obvious to aperson skilled in the art having the benefit of this disclosure. It isintended to embrace all such modifications and changes and, accordingly,the above description is to be regarded in an illustrative rather than arestrictive sense.

What is claimed is:
 1. A system, comprising: at least one processor; amemory coupled to the at least one processor, wherein the memory storesprogram instructions, wherein the program instructions are executable bythe at least one processor to: automatically select one or more optimalparameter values for a service on a test computer, wherein, for each ofa plurality of test parameter values for the service on the testcomputer, the program instructions are executable by the at least oneprocessor to execute one or more load tests on the test computer,wherein the one or more optimal parameter values are automaticallyselected from among the plurality of test parameter values based atleast in part on a corresponding performance of the service on the testcomputer for different ones of the plurality of test parameter values;automatically determine a performance of the service on a plurality ofadditional test computers configured with the one or more optimalparameter values, wherein the program instructions are executable by theat least one processor to execute a plurality of additional load testson the plurality of additional test computers; automatically configurethe service on a plurality of production computers with the one or moreoptimal parameter values responsive to detection of improvement of aperformance of the service on the plurality of additional test computerswith the one or more optimal parameter values, in comparison with abaseline performance of the service on the plurality of additional testcomputers configured with other parameter values that differ from theone or more optimal parameter values; and discard the one or moreoptimal parameter values responsive to detection that the performance ofthe service on the plurality of additional test computers does notexceed the baseline performance of the service on the plurality ofadditional test computers.
 2. The system as recited in claim 1, whereinthe program instructions are further executable by the at least oneprocessor to: automatically determine a performance of the service onthe plurality of production computers configured with the one or moreoptimal parameter values; and automatically restore one or more earlierparameter values of the service on the plurality of production computersif the performance of the service with the one or more optimal parametervalues is not superior to an earlier performance with the one or moreearlier parameter values.
 3. The system as recited in claim 1, whereinthe program instructions are further executable by the at least oneprocessor to: receive a user-defined performance goal; wherein the oneor more optimal parameter values are automatically selected to meet theuser-defined performance goal.
 4. The system as recited in claim 1,wherein the program instructions are further executable by the at leastone processor to: receive a user-defined testing frequency; whereinautomatically selecting the one or more optimal parameter values isscheduled according to the user-defined testing frequency.
 5. The systemas recited in claim 1, wherein the program instructions are furtherexecutable by the at least one processor to: automatically provision theplurality of test computers from among the plurality of productioncomputers.
 6. The system as recited in claim 1, wherein the programinstructions are further executable by the at least one processor to:automatically provision the plurality of test computers from among apool of available test computers, wherein the plurality of testcomputers are selected based on a similarity to the plurality ofproduction computers.
 7. A method, comprising: automatically selectingone or more optimal parameter values for a service on a test computer,comprising, for each of a plurality of test parameter values for theservice on the test computer, executing one or more load tests on thetest computer, wherein the one or more optimal parameter values areautomatically selected from among the plurality of test parameter valuesbased at least in part on a corresponding performance of the service onthe test computer for different ones of the plurality of test parametervalues; automatically determining a performance of the service on aplurality of additional test computers configured with the one or moreoptimal parameter values, comprising executing a plurality of additionalload tests on the plurality of additional test computers; automaticallyconfiguring the service on a plurality of production computers with theone or more optimal parameter values responsive to detection ofimprovement in a performance of the service on the plurality ofadditional test computers with the one or more optimal parameter values,compared with a baseline performance of the service on the plurality ofadditional test computers configured with other parameter values thatdiffer from the one or more optimal parameter values; and discarding theone or more optimal parameter values responsive to detection that theperformance of the service on the plurality of additional test computersdoes not exceed the baseline performance of the service on the pluralityof additional test computers.
 8. The method as recited in claim 7,further comprising: automatically determining a performance of theservice on the plurality of production computers configured with the oneor more optimal parameter values; and automatically restoring one ormore earlier parameter values of the service on the plurality ofproduction computers if the performance of the service with the one ormore optimal parameter values is not superior to an earlier performancewith the one or more earlier parameter values.
 9. The method as recitedin claim 7, further comprising: receiving a user-defined performancegoal; wherein the one or more optimal parameter values are automaticallyselected to meet the user-defined performance goal.
 10. The method asrecited in claim 7, further comprising: receiving a user-defined testingfrequency; wherein automatically selecting the one or more optimalparameter values is scheduled according to the user-defined testingfrequency.
 11. The method as recited in claim 7, further comprising:automatically provisioning the plurality of test computers from amongthe plurality of production computers.
 12. The method as recited inclaim 7, further comprising: automatically provisioning the plurality oftest computers from among a pool of available test computers, whereinthe plurality of test computers are selected based on a similarity tothe plurality of production computers.
 13. The method as recited inclaim 7, further comprising: automatically determining one or moreconfigurable parameters in the test computer; automatically determininga range of values for the one or more configurable parameters; and foreach of the plurality of test parameter values, automatically assigningrespective values for the configurable parameters within the range ofvalues.
 14. The method as recited in claim 7, further comprising:automatically generating a plurality of test loads using a hill-climbingloop, wherein each successive iteration of the hill-climbing loopincreases a frequency of transactions; wherein the plurality of loadtests are performed using the test loads.
 15. A computer-readablestorage medium storing program instructions computer-executable toperform: automatically selecting one or more optimal parameter valuesfor a service on a test computer, wherein, for each of a plurality oftest parameter values for the service on the test computer, the programinstructions are executable by at least one processor to execute one ormore load tests on the test computer, wherein the one or more optimalparameter values are automatically selected from among the plurality oftest parameter values based at least in part on a comparison ofcorresponding performance of the service on the test computer fordifferent ones of the test parameter values; automatically determining aperformance of the service on a plurality of additional test computersconfigured with the one or more optimal parameter values, wherein theprogram instructions are executable by the at least one processor toexecute a plurality of additional load tests on the plurality ofadditional test computers; automatically configuring the service on aplurality of production computers with the one or more optimal parametervalues responsive to detection of improvement of a performance of theservice on the plurality of additional test computers with the one ormore optimal parameter values, in comparison with a baseline performanceof the service on the plurality of additional test computers configuredwith other parameter values that differ from the one or more optimalparameter values; and discarding the one or more optimal parametervalues responsive to detection that the performance of the service onthe plurality of additional test computers does not exceed the baselineperformance of the service on the plurality of additional testcomputers.
 16. The computer-readable storage medium as recited in claim15, wherein the program instructions are further computer-executable toperform: automatically determining a performance of the service on theplurality of production computers configured with the one or moreoptimal parameter values; and automatically restoring one or moreearlier parameter values of the service on the plurality of productioncomputers if the performance of the service with the one or more optimalparameter values is not superior to an earlier performance with the oneor more earlier parameter values.
 17. The computer-readable storagemedium as recited in claim 15, wherein the program instructions arefurther computer-executable to perform: receiving a user-definedperformance goal; wherein the one or more optimal parameter values areautomatically selected to meet the user-defined performance goal. 18.The computer-readable storage medium as recited in claim 15, wherein theprogram instructions are further computer-executable to perform:receiving a user-defined testing frequency; wherein automaticallyselecting the one or more optimal parameter values is scheduledaccording to the user-defined testing frequency.
 19. Thecomputer-readable storage medium as recited in claim 15, wherein theprogram instructions are further computer-executable to perform:automatically provisioning the plurality of test computers from amongthe plurality of production computers.
 20. The computer-readable storagemedium as recited in claim 15, wherein the program instructions arefurther computer-executable to perform: automatically provisioning theplurality of test computers from among a pool of available testcomputers, wherein the plurality of test computers are selected based ona similarity to the plurality of production computers.